DE202010011948U1 - Implant system for the fusion of vertebral bodies - Google Patents

Abstract

Implant system for the fusion of vertebral bodies, with:
a) an implant (50) which has an implant length (IL) along a longitudinal axis and is adapted to be screwed into an intervertebral disc space (70) bounded by two vertebrae (W1, W2),
b) a guide sleeve (10), through which the implant (50) is screwed into the intervertebral disc space (70) and which is supported during the screwing operation with a shoulder (36, 38) on the two vertebrae (W1, W2), and With
c) a drill (40) which is insertable from a proximal, the surgeon facing the end of the guide sleeve (10) forth in this and a shaft (42) which carries at its distal, the surgeon end facing a drill head (46) .
characterized in that
on the shank (42) of the drill (40) a stop (48) is formed, which cooperates with the guide sleeve (10) such that further insertion of the drill (40) in the guide sleeve (10) is prevented as soon as .. ,

Description

BACKGROUND OF THE INVENTION

1. Field of the invention

The The invention relates to an implant system for fusion of vertebral bodies delimiting an intervertebral disc space. The system comprises an implant to be screwed in, a guide sleeve and a drill.

2. Description of the state of the technique

at degenerated spinal segments is a treatment option It is to remove the affected disc completely or partially and insert an implant into the disc compartment. Often the implant is provided with an external thread and can thereby screwed into the prepared disc compartment become. The implant holds the adjacent vertebrae Distance and allows the disc space to and ossified, eventually becoming a merger the adjacent vortex leads.

An example of such an implant is in the US 2007/0055374 A1 described. The known implant has a rounded head with a conical threaded portion, a central portion with large windows and a base portion having fastening means for a driver. The base section has different dimensions in two orthogonal directions. By rotating the implant by 90 ° different angles between the adjacent vertebral bodies can thus be adjusted.

Before the implant can be screwed in, the disc compartment must usually be distracted. For this purpose, for example, a System of several coordinated guide sleeves and distractors are used as it is in the unpublished German patent application "System for distracting a Disc compartment "of the applicant is described on 24.08.2010 was submitted.

To Two disturctions protrude at the distal ends of the guide sleeves protruding spacers into the disc compartment and get into upright distraction. After removing the last distractor can through the last used guide sleeve a Eindrehinstrument be introduced at the distal End of the implant is attached.

Occasionally However, it can happen that the two adjacent vertebrae are not Distract so far that the implant is in the disc space can be introduced. In such cases it is expedient, the disc compartment first Drill with the help of a drill.

The Boring the disc compartment is also with disadvantages connected. On the one hand, hard bone material in the area of Edges of the vertebral bodies are removed, potentially the stability of the vertebral body weakens. On the other hand, the boring is not free of risks, as the drill to the posterior margins of the adjacent vertebral bodies is introduced. Beyond these bony edges There is sensitive tissue such as blood vessels, which is why drilling in this area require special attention of the surgeon.

One Another problem arises from the fact that the surgeon in general selects an implant before surgery, after insertion the disc compartment receives a desired target geometry. During the operation, the surgeon realizes that he is Do not distract the neighboring vertebrae far enough can and therefore the disc tray must be drilled up, so This usually requires that then another than that originally planned implant must be screwed. This increases the complexity of the surgical Process and also the number of implants used for the Operation must be kept. Both have an unfavorable effect on the cost of treatment.

SUMMARY OF THE INVENTION

task The invention is an implant system with a einzudrehenden Implant, a guide sleeve and a drill indicate the disadvantages described above, which in Connection with the boring can arise, at least partially overcomes.

This object is achieved according to the invention by an implant system for the fusion of vertebral bodies, which comprises a (preferably provided with an external thread) implant, which has an implant length along a longitudinal axis and is adapted to be screwed into a limited by two vertebrae disc space , The implant system further comprises a guide sleeve, through which the implant is screwed into the intervertebral disc compartment and which is supported during the screwing operation with a shoulder on the two vertebrae. Furthermore, the implant system comprises a drill, which can be introduced into it from a proximal, surgeon-facing end of the guide sleeve and has a shaft which carries a drill head at its distal end facing away from the surgeon. According to the invention is on the Shank a stop formed, which cooperates with the guide sleeve such that further insertion of the drill is prevented in the guide sleeve as soon as the drill reaches an axial stop position relative to the guide sleeve. In this axial stop position, the drill head projects beyond the shoulder of the guide sleeve by a drill length which is smaller than the implant length.

With In other words, the bore produced by the drill bit is always shorter as the implant. The intervertebral disc is thus not drilled over the entire length of the implant or even more out, but only within a shorter proximal, d. H. the surgeon facing section.

behind it The consideration is that many are common Implant geometries on a boring of the distal, by the surgeon facing away from bone edges of the disc space limiting vertebral body can be waived. Because there is the distance between the vertebral bodies, if they are in a distracted position during surgery are the biggest anyway. Problematic, because in a sense "too narrow", is rather the proximal end of the disc compartment, because there is distracted in the Position the distance between the vertebral bodies in the Usually smaller. Therefore, it is generally difficult to the thicker front section of the implant into the disc compartment introduce.

According to the invention therefore only this closer proximal end of the disc compartment drilled out with the help of the drill. The attack ensures that that the drill no longer than absolutely necessary in the Intervertebral disc can penetrate. There is no danger that lying behind the distal end of the vertebral body sensitive tissue is damaged by the drill. In addition, by a short bore stability the vertebral body less affected.

Especially Advantageously, the invention is thus applicable when the implant its largest diameter in its distal, d. H. facing away from the surgeon during the insertion procedure, Half has.

at In a preferred embodiment, the implant has essentially the shape of a double cone. The section where the two bicone adjacent to each other, then at the same time the section with the largest diameter of the Implant.

There generally only the proximal bone margins facing the surgeon the adjacent vertebral body must be drilled out, For example, the bore length can be relatively short, and for example less than 2/3 or even 1/2 of the implant length.

at a particularly preferred embodiment has the Implant at its proximal, d. H. during the driving-in process facing the surgeon, end a base section that runs along two directions perpendicular to the longitudinal axis of the Implant run, has different dimensions.

ever according to the angular orientation in which the implant in the disc space remains, resulting in different angles between the adjacent vertebral bodies.

This can in turn be used to compensate for to create the material removal, possibly caused by a drilling process becomes. The dimensions along the two directions are then such adapted to the diameter of the drill head, that then when with the Drill a hole was made and the implant in a first angular position between the vertebral bodies, the distance and the angle between the angle bodies equal is great, as if with the drill no hole was created and the implant is in a second angular position, by rotation (in orthogonal directions by 90 °) from the first angular position emerges.

On this way gives the surgeon the ability to regardless of whether he with the help of the drill the intervertebral disc drilled or not, a predetermined geometry of the disc compartment with to reach one and the same implant. The different ones Dimensions of the base section are designed so that they compensate for the material removal that occurs in the event of a bore and initially change the geometry of the disc space would. Depending on whether a hole is created or not, the implant is transferred to the first or the second angular position, as soon as it reaches its axial target position in the disc space Has.

The Guide sleeve can have two at its distal end Have spacers that are perpendicular to the longitudinal direction of Sleeve have a width and which, when the guide sleeve with the shoulder supported on two vertebrae, the disc compartment hold in a distracted position so that in the absence of the Implant the distance between the vertebral bodies same the width of the spacers is.

In order to achieve a balance of the material of the material removal by the drill, then the difference between the dimensions of Basi Section in the two directions equal to the difference between the bore diameter produced by the drill head and the width of the distance tongues.

Stand several drills available, the drill bits with have different diameters, or more guide sleeves with the same inner diameter, but with different width spacers, available, so the base section can also be in more as two directions have different dimensions. With a Base section, which in cross-section the shape of an irregular Hexagon has, let, for example, three different Set distances.

Around Finally, the implant through the guide sleeve to be able to screw into the disc compartment, the system include a driver on which the implant is releasable attachable and through the guide sleeve therethrough in the belt disc compartment is screwed. An example for a suitable driver is submitted in the same day German patent application entitled "Instrumentarium for screwing an implant into an intervertebral disc compartment " Applicant described.

object The invention further includes an implant system for fusion of vertebral bodies, the one (preferably with an external thread provided implant, which is adapted to, in a to be screwed by two vertebra limited disc space. The implant has at its proximal, d. H. during the Driving operation facing the surgeon, end a base section, along two directions perpendicular to the longitudinal axis of the implant, has different dimensions. The Implant system further comprises a guide sleeve, through which the implant is screwed into the disc compartment and has at its distal end two spacers which are perpendicular to the longitudinal direction of the guide sleeve a Have width and which, when the guide sleeve with the shoulder on the two vertebrae supporting the intervertebral disc space hold in a distracted position so that in the absence of the implant the distance between the vertebral bodies equal to the width the distance tongues is. Furthermore, the implant system comprises a Drill from a proximal end facing the surgeon Guide sleeve ago in this insertable is and has a shaft attached to its distal, the surgeon opposite end carries a drill head. According to the invention the dimensions of the base section along the two directions adapted to the diameter of the drill head such that when With the drill a bore was created and the implant in a first angular position between the vertebral bodies located, the distance and the angle between the vertebral bodies is the same size as if with the drill no hole was generated and the implant position in a second angle is found by rotation from the first angular position.

BRIEF DESCRIPTION OF THE DRAWINGS

Further Features and advantages of the invention will become apparent from the following Description of an embodiment with reference to the drawings. Show:

1 a perspective view of a guide sleeve, which is a component of the system according to the invention;

2 a front view of the in the 1 shown guide sleeve;

3 a side view of the in the 1 shown guide sleeve;

4 a soffit of the in the 1 shown guide sleeve;

5 a side view of a drill, which is another component of the system according to the invention;

6 an enlarged perspective view of an implant, which is also a component of the system according to the invention;

7 a side view of an inserted into the disc compartment guide sleeve with a drill inserted therein;

8th a side view like 7 , but with cut open guide sleeve;

9 a side view of the implanted in the disc space implant in its axial nominal position and a first angular position;

10 the implant as in the 9 but in a second angular position;

11 a bottom view of the introduced into the disc tray implant in the first angular position;

12 a bottom view of the inserted into the disc tray implant in the second angular position.

DESCRIPTION OF PREFERRED EMBODIMENTS

I. Construction

The Implant system according to the invention comprises a Implant, a guide sleeve and a drill. Preferably, these components are each multiple, but with different Dimensions available to different angles and distances to be able to adjust between the vertebral bodies, which should merge.

a) guide sleeve

The structure of one of the guide sleeves will be described below with reference to the 1 to 4 described in more detail. These figures show the guide sleeve in a perspective view, a front view, a side view and a bottom view, respectively.

The total with 10 designated guide sleeve has a proximal end which faces up in the figures and in the use of the guide sleeve 10 during surgery to the surgeon. The opposite, in the 1 to 3 downwardly facing end of the guide sleeve 10 is referred to as the distal end. With the distal end in front is the guide sleeve 10 introduced during operation through a previously exposed access opening in the patient.

The guide sleeve 10 has a substantially circular cross-section; However, others are possible, for. B. square, cross sections. Parallel to a longitudinal axis 12 the guide sleeve 10 extends a longitudinal slot 14 , throughout from the proximal end to the distal end of the guide sleeve 10 ,

At the proximal end of the guide sleeve 10 are two protrusions 20 . 22 formed, which are diametrically opposed to each other and radially from the longitudinal axis 12 the guide sleeve 10 protrude. The proximal end surfaces of the two projections 20 . 22 form contact surfaces 24 . 26 that are flat and perpendicular to the longitudinal axis 12 the guide sleeve 10 run. The contact surfaces 24 . 26 can be used with a hammer or other impactor the distal end of the guide sleeve 10 to drive into the disc compartment. This also succeeds when from the proximal end of the guide sleeve 10 another instrument, eg. As a drill or a Eindrehinstrument protrudes, previously in the guide sleeve 10 was introduced. Between the projections 20 . 22 extends a footbridge 27 , which is slightly lower in the axial direction than the projections 20 . 22 , The jetty 27 serves in a manner to be explained as a counter surface for a trained on the drill stopper ring.

At its distal end, the guide sleeve 10 two diametrically opposed recesses 28 . 30 on, between which two distance tongues 32 . 34 remain facing each other. The distance tongues 32 . 34 are thus formed by a portion of the guide sleeve wall, but are rounded to the distal end approximately elliptical, as best seen in the side view of 3 can recognize.

The proximal end face of the recess 28 forms a first support shoulder 36 (please refer 3 and 4 ) while the opposite recess 30 due to the longitudinal slot running there 14 two narrower second support shoulders 38 sets.

As in the 3 and 4 recognizable, the two have spacers 32 . 34 along a transverse direction perpendicular to the longitudinal axis 12 runs, a width b. If the system has multiple guide sleeves 10 includes, they differ at least by the widths b of the Distanzzungen 32 . 34 from each other, but possibly also by the inner and outer diameter of the guide sleeves 10 ,

b) Drill

The 5 shows in a side view with a total of 40 designated drill, which is also a component of the system according to the invention. The drill has a substantially rod-shaped shaft 42 , at the proximal end of a handle 44 is formed. At the opposite distal end of the shaft carries 42 a drill head 46 , which in a conventional manner with inclined drill bits 47 is provided.

On the shaft 42 is also a stopper ring 48 formed, whose diameter is greater than the inner diameter of the guide sleeve 10 ,

Between the stop ring 48 and the drill head 46 is the shaft 42 with several annular guide beads 49 Mistake. The diameter of the guide beads 49 is slightly smaller than the inner diameter of the guide sleeve 10 so that the drill bit 40 in the guide sleeve 10 can be guided without tilting.

c) implant

The 6 shows in an enlarged perspective view obliquely from the front with a total of 50 denote tes implant, which is also a component of the system according to the invention. The implant 50 has a rough approximation of a cylindrical basic shape, but the scope surfaces predominantly slightly inclined to a longitudinal axis of the implant 50 run. The largest diameter lies in the front, in the 6 to the viewer facing half of the implant 50 , so that the basic shape of the implant 50 more accurately described as a double cone.

The implant has a base section 52 , a central section 54 and a head section 56 , The head section 56 runs to the distal, in the 6 to the viewer facing end of the implant 50 conical too and is with an external thread 58 provided, which is seamlessly at the central section 54 continues. The part of the head section immediately adjacent to the distal end 56 is thread-free and forms a rounded protective cap 60 , the ring-shaped an end opening 62 surrounds.

The central section 54 is with four evenly distributed over the circumference and elongated in the axial direction windows 64 provided in which the external thread 58 is interrupted and each with several circular openings 66 release. After the implant 50 In the intervertebral disc space, bone tissue may be the implant 50 through the openings 66 grow through it and bring about in this way the desired fusion of the adjacent vertebral bodies.

The base section 52 is essentially formed as a four-flat, but in two mutually orthogonal directions, both to the longitudinal direction of the implant 50 are orthogonal, has different dimensions. Visible this is good in the 11 and 12 showing the implant in two different angular positions in the implanted state. The widths of the implant 50 in these two directions there are designated a ₁ and a ₂ .

The two wider mutually parallel planar surfaces, which have the smaller distance to each other, each having a groove 68 Mistake. In the grooves 68 projections of a driving instrument can engage in a form-fitting manner around the implant 50 rotatably determined on the driver. Inside the base section 52 is still provided with an internally threaded bore, with which the implant 50 can be releasably fixed to the insertion instrument in the axial direction. In the 11 and 12 this hole is recognizable and with 71 designated.

Further details of the implant are mentioned above US 2007/0055374 A1 removable.

II. Use

In order to make the interaction of the components described above in I. to understand, are in the following with reference to the 7 to 12 It explains some of the steps involved in inserting the implant 50 in an intervertebral disc compartment are required.

In a first step it is determined which of several implants 50 to be used with different dimensions in the disc space. This determination is usually based on functional recordings of the affected spinal column segment. This is a sequence of X-ray images in which the affected segment is shown in different states of motion (eg inclination, reclination, lateral flexion). The surgeon then determines at what distance and at what angle to each other the vertebral disc limiting vertebra after insertion of the implant (in general, however, two identical implants are placed side by side) should be arranged. Optionally, the treating surgeon is assisted by a computer program that issues a recommendation for an optimal implant geometry taking into account the biometric features of the patient to be treated.

In in a second step, access to the disc space is exposed. This may be, for example, a posterior-lateral approach act. In most cases, then the intervertebral disc completely or partially removed. The limiting the disc space Vertebral bodies generally move towards each other too, causing the height of the disc space initially reduced.

In a third step, the intervertebral disc space is distracted. The distraction can be performed, for example, stepwise using several differently sized guide sleeves and distractors, as described in the above-mentioned unpublished German patent application entitled "System for Distracting an Intervertebral Disc". The last guide sleeve 10 is a guide sleeve on the implant to be used 50 is tuned. This means that the inner diameter of the guide sleeve 10 is slightly larger than the outer diameter of the previously selected implant 50 , Only then can the implant be guided through the guide sleeve with the aid of a driver 10 slide and screw into the disc compartment.

The 7 and 8th show the guide sleeve 10 in a side view, wherein the guide sleeve 10 in the 8th is cut to the drill guided therein 50 to recognize better. The guide sleeve 10 sticks out with their distance tongues 32 . 34 in one with 70 designated disc space inside, which is bounded by two vertebral bodies W1, W2 shown in section. The guide sleeve 10 relies with her shoulders 36 . 38 at the edges of the vertebral bodies W1, W2. Shoulders 36 . 38 thus serve as a stop and reliably prevent further penetration of the guide sleeve 10 into the disc compartment 70 ,

It is assumed here by way of example that the implant has a maximum core diameter d _K = 8 mm and an outer diameter (ie taking into account the external thread 58 ) d _A = 10 mm. The dimensions of the base section 52 be a ₁ = 7 mm and a ₂ = 5. The inner diameter of the guide sleeve 10 is, as mentioned above, slightly larger than the outer diameter of the implant 50 , On the guide sleeve is the core diameter d _{K of} the implant, for which the guide sleeve 10 is suitable by a at 72 engraved number (here 8) displayed.

If the disc compartment 70 can be distracted to 10 mm, so after completion of the distraction a guide sleeve 10 used, whose distance tongues 32 . 34 have a width b = 10 mm. In this case, the implant could 10 easily in the distracted to 10 mm disc compartment 70 be introduced, since its outer diameter d _{A is} also 10 mm.

However, it may happen that the distraction ability of the disc space 70 limiting vertebra W1, W2 is insufficient to the disc space 70 to distract to 10 mm. Cause this can be z. B. be a particularly firing ligament apparatus surrounding the vertebral bodies W1, W2. In order not to damage this ligamentous apparatus, the distraction of vertebral bodies W1, W2 should be made gently; overstretching is to be avoided.

In the illustrated embodiment, it is assumed that a distraction of the disc space 70 only possible on 8 mm. Therefore, the used after completion of the distraction and in the 7 shown in side view guide sleeve 10 Spacer tongues whose width b is only 8 mm.

So that the implant with an outer diameter d _A = 10 mm can still be screwed into the disc compartment, one could consider the implant with its external thread 58 in the proximal, in the 7 and 8th have the upper edges of the vertebral bodies W1, W2 cut. However, these bony edges would be ridged and thereby destabilized. It should be taken into account that in the axial nominal position of the implant 50 as they are in the 9 and 10 is shown, the implant not with a threaded portion, but with the parallelepiped of the base portion 52 rests against these bony edges. In order to avoid destabilization of the bone margins, it is better to the disc compartment 70 with the help of the drill 40 drilled to 10 mm, leaving the implant 50 can be introduced easily.

The guide sleeve 10 indicates this 74 by how many millimeters the distance b of the spacers 34 . 36 is smaller than the outer diameter d _{A of} an implant 50 whose core diameter d _K = 8 mm. In the illustrated embodiment, this difference is 2 mm. Consequently, a drill needs 40 whose drill head is 2 mm larger than the core diameter (8 mm) of the implant 50 , hence a drill with a drill head 46 whose diameter is 10 mm. As a rule, it is sufficient if for each core diameter d _{K of} the implant 50 only a drill 40 is provided, which has a bore with the outer diameter d _{A of} the implant 50 generated. Therefore, the surgeon simply needs only for the core diameter d _K = 8 mm provided drill 40 (see caption at 75 in 8th ) to use.

This drill 46 will now be in a fourth step with his drill head 46 ahead in the guide sleeve 10 introduced until the drill head 46 at the bone edges of the vertebral bodies W1, W2 strikes. By turning the handle 44 then becomes the drill head 46 set in rotation about its longitudinal axis and thus machined produces a bore with a diameter of 10 mm. This hole is big enough to fit the implant 50 then to be able to introduce into the hole. The drill head 46 removed while drilling bone material that in the 7 and 8th through thick black lines 76 on both sides of the viewer facing the spacer tongue 34 is indicated.

During the drilling process, the drill head penetrates 46 ever further into the disc space 70 one. This penetration process ends at the moment at which the shaft 42 of the drill 40 molded stop ring 48 at the footbridge 27 the guide sleeve 10 strikes. How to get in the 8th in which the guide sleeve 10 is cut open, can see well enough in this axial stop position of the drill head 46 of the drill 40 only a relatively short distance into the disc space 70 into it. The indicated with BL drilling length of the drill 40 is even less than the axial length of the spacers 32 . 34 , In particular, however, the drilling length BL is significantly smaller than that in the 9 recognizable implant length IL of the implant 50 , However, the relatively small bore length BL suffices for the implant 50 with the comparatively thick Kopfab cut 56 in the intervertebral disc space 70 to be able to introduce.

However, a short bore BL also alters the geometry of the disc compartment 70 on the proximal, in the 7 and 8th upwards facing page. To compensate for this, the different dimensions a ₁ , a _{2 of} the base section 52 of the implant 50 so to the diameter of the drill head 46 adjusted that, then, if with the drill 40 a hole was made and the implant 50 is in a first angular position between the vertebral bodies W1 and W2, the distance and the angle between the vertebral bodies W1, W2 is the same size as when with the drill 40 No drilling would have been made and the implant 50 is in a second angular position, which emerges here by rotation by 90 ° from the first angular position.

This is in the 11 and 12 shown a soffit of the implant 50 show in the first and in the second angular position after the implant 50 completely into the disc compartment 70 was screwed in. In the in the 11 shown first angular position is the base portion 52 of the implant 50 oriented so that the side with the greater width a ₁ extends parallel to a direction indicated by a double arrow direction L, which runs approximately parallel to the longitudinal axis of the spine of the patient. Because of the previously carried out drilling the base section 52 of the implant 50 in this first angular position a little into the vertebral bodies W1, W2. Since the hole has a diameter that is 2 mm larger than the distraction of the disc compartment 70 , This immersion depth is at each of the vertebral bodies W1, W2 each 1 mm.

If, however, renounced a hole because the disc compartment 70 previously distilled to 10 mm, then the implant becomes 50 in the in the 12 used shown by the second angular position, by rotation through 90 ° from the in 11 shown first angular position emerges. In this second angular position is the base section 52 of the implant 50 is oriented so that the side with the smaller width a ₂ extends parallel to the direction L. The difference between the two widths a ₁ - a ₂ = 2 mm thus compensates exactly the material removal, by the drill 40 when drilling the disc compartment 70 in the adjacent vertebral bodies W1, W2 at 76 was generated.

Consequently, in the 11 and 12 A labeled distance between the vertebral bodies W1, W2 at the proximal end in both angular positions of the implant 50 identical, namely a ₂ = 5 mm.

The same applies to the angle α between the vertebral bodies W1, W2. In addition to this is in addition to the 10 referenced in which the implant 50 compared to the one in the 9 shown second angular position in the first angular position in the disc space 70 is arranged. The angle α between the two the disc compartment 70 limiting vertebrae W1, W2 is identical in both cases and thus does not depend on whether previously the disc space 70 was drilled or not.

Thus, since the distance A and also the angle α between the vertebrae W1, W2 is identical irrespective of whether or not a bore has been previously created, in each case the same predetermined geometry of the intervertebral disc space will be used 70 through the implant 50 set.

By the rotation of the implant 50 by 90 ° to change between the first and the second angular position is in principle also the axial position of the implant 50 in the intervertebral disc space 70 slightly changed. Due to the almost double conical shape of the implant 50 This also affects the geometry of the disc compartment 70 out. The slope of the external thread 58 of the implant 50 However, it is so small that the axial displacement of the implant 70 significantly less than 1 mm when rotated by 90 °. The concomitant change in the geometry of the disc space 70 is therefore negligible.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• US 2007/0055374 A1 [0003, 0055]

Claims (9)

Implant system for the fusion of vertebral bodies, comprising: a) an implant ( 50 ), which has an implant length (IL) along a longitudinal axis and is adapted to move into a disc space bounded by two vertebrae (W1, W2) ( 70 ) to be screwed, b) a guide sleeve ( 10 ), through which the implant ( 50 ) into the intervertebral disc space ( 70 ) is screwed in and during the Einrehvorgangs with a shoulder ( 36 . 38 ) is supported on the two vertebrae (W1, W2), and with c) a drill ( 40 ), which depends on a proximal, the surgeon-facing end of the guide sleeve ( 10 ) is inserted into this and a shaft ( 42 ), which at its distal, the surgeon end facing away from a drill head ( 46 ), characterized in that on the shaft ( 42 ) of the drill ( 40 ) an attack ( 48 ) is formed, which with the guide sleeve ( 10 ) cooperates such that further insertion of the drill ( 40 ) in the guide sleeve ( 10 ) is prevented as soon as the drill ( 40 ) relative to the guide sleeve ( 10 ) reaches an axial stop position, and that the drill head ( 46 ) in the axial stop position by a drilling length (BL) over the shoulder ( 36 . 38 ) of the guide sleeve ( 10 ), which is smaller than the implant length (IL). Implant system according to claim 1, characterized in that the implant ( 50 ) has its largest diameter in its distal, that is facing away from the surgeon during the Eindrehvorgangs, half. Implant system according to claim 2, characterized in that the implant ( 50 ) essentially has the basic shape of a double cone. Implant system according to one of the preceding claims, characterized in that the drilling length (BL) is smaller is 2/3 of the implant length (IL). Implant system according to claim 4, characterized in that that the drilling length (BL) is less than 1/2 of the implant length (IL) is. Implant system according to one of the preceding claims, characterized in that the implant ( 50 ) at its proximal end, ie during the screwing operation towards the surgeon end, a base portion ( 52 ) that has different dimensions (a ₁ , a ₂ ) along two directions that are perpendicular to the longitudinal axis of the implant. Implant system according to claim 6, characterized in that the dimensions (a ₁ , a ₂ ) along the two directions in such a way to the diameter of the drill head ( 46 ) are adapted, that when, with the drill ( 40 ) a bore has been created and the implant ( 50 ) is in a first angular position between the vertebral bodies (W1, W2), the distance (A) and the angle (α) between the vertebral bodies (W1, W2) is the same, as when with the drill ( 40 ) no hole was created and the implant ( 50 ) is in a second angular position, which emerges by rotation from the first angular position. Implant system according to one of the preceding claims, characterized in that the guide sleeve ( 10 ) at its distal end two spacers ( 32 . 34 ) perpendicular to the longitudinal direction ( 12 ) of the sleeve ( 10 ) have a width (b) and which, when the guide sleeve ( 10 ) with the shoulder ( 36 . 38 ) is supported on the two vertebrae (W1, W2), the intervertebral disc space ( 70 ) in a distracted position so that in the absence of the implant ( 50 ) the distance between the vertebral bodies (W1, W2) equal to the width (b) of the spacers ( 32 . 34 ). Implant system according to claim 8 when referring back to claim 7, characterized in that the difference between the dimensions (a ₁ , a ₂ ) of the base portion ( 52 ) in the two directions is the difference between the bore diameter produced by the drill head and the width of the spacer tongues (b).